Conventionally, for example, a technique of pasting a hologram on a surface of an article or a technique of applying a special ink on a surface of an article have been known as methods to stop counterfeiting of articles such as cards and security notes. (for example, Japanese Utility Model Application Laid-Open No. 2001-315243, page 2, claim 14). In a technique in which the hologram is used, the authenticity of the article on which the hologram is pasted is determined by viewing the hologram, which appears to be three-dimensional or varies in color depending on the viewing angle. In a technique in which a special ink is used, for example fluorescent ink or magnetic ink may be used as the special ink. The authenticity of the article on which the above ink is applied is determined by sensing information hidden in the above ink by irradiating ultraviolet light thereon or by magnetic sensors although the above ink may be viewed in the same manner as normal inks. Moreover, examples using an ink or a film made from cholesteric liquid crystal are well known as an identifying medium for objects such as cards and security notes for an anti counterfeiting method using a film in which the reflective characteristics of light depends on the viewing and the light is selectively reflected (for example, Japanese Patent No. 3244278, page 7, and FIGS. 1 and 2).
However, if it is desired to obtain high performance of identification only using holograms, high cost technology is required to the holograms, and the holograms cannot be used on some kinds of objects. In addition, counterfeiting is easy since inks similar to the fluorescent ink and the magnetic ink can be easily obtained, and an apparatus for confirming is large and requires a power supply, whereby use there of is inconvenient. Moreover, the production cost for the identifying medium for objects is high since the price of the cholesteric liquid crystal used therein is relatively high, and the medium is not suitable for low-price goods.
Therefore, an object of the present invention is to provide a discrimination medium by which counterfeiting can be prevented, authenticity of articles can be easily and reliably determined, and the production cost can be low.